1. Field of the Invention
The present invention relates to a fluid sensor for determining a fluid characteristic, having an electronic sensor element that has an active surface for determining the fluid characteristic, having a mounting plate associated with the sensor element, and having a filter device associated with the sensor element for filtering the fluid, in which the active surface of the sensor element is oriented toward the mounting plate and in which the mounting plate is provided with an opening opposite from the active surface of the sensor element,
2. Description of the Background Art
A conventional fluid sensor is embodied in the form of a tire pressure sensor and is provided for mounting in a valve region of a motor vehicle tire. The conventional fluid sensor is equipped with an electronic sensor element that has an active surface embodied in the form of a pressure sensing membrane. The sensor element is attached to a mounting plate that is equipped with a separately manufactured, hollow cylindrical holder for the filter device. The hollow cylindrical holder is provided for a fluid-tight connection between the filter device and the sensor element. The function of the filter device is to keep foreign matter such as dirt particles that can be contained in the fluid, particularly in a gas or liquid, away from the active surface of the sensor element in order to prevent damage to the sensor element. To this end, the filter device is manufactured of a porous material, typically an open-pored polytetrafluoroethylene material. Concentric to the recess in the hollow cylindrical holder, an opening is provided in the mounting plate. Consequently, the sensor element can be attached to a side of the mounting plate oriented away from the hollow cylindrical holder and is communicatively connected to the filter device through the opening. In order to assure tightness, the hollow cylindrical holder is accommodated on the mounting plate in a sealed fashion. Several assembly steps are required to manufacture the fluid sensor, particularly including the joining of the hollow cylindrical holder to the mounting plate and the fitting of the filter device into the hollow cylindrical holder.